Conduct fabric-filtered read on CurrentSessions attribute

Author: yufengwangca

src/app/clusters/webrtc-transport-provider-server/webrtc-transport-provider-server.cpp

@@ -91,11 +91,16 @@ CHIP_ERROR WebRTCTransportProviderServer::Read(const ConcreteReadAttributePath &
     // which is a list[WebRTCSessionStruct].
     if (aPath.mClusterId == Id && aPath.mAttributeId == Attributes::CurrentSessions::Id)
     {
-        // We encode mCurrentSessions as a list of WebRTCSessionStruct
-        return aEncoder.EncodeList([this](const auto & encoder) -> CHIP_ERROR {
+        // CurrentSessions is a fabric-scoped attribute that must only return sessions belonging to the accessing fabric.
+        FabricIndex accessingFabricIndex = aEncoder.AccessingFabricIndex();
+        return aEncoder.EncodeList([this, accessingFabricIndex](const auto & encoder) -> CHIP_ERROR {
             for (auto & session : mCurrentSessions)
             {
-                ReturnErrorOnFailure(encoder.Encode(session));
+                // Only encode sessions that belong to the accessing fabric
+                if (session.GetFabricIndex() == accessingFabricIndex)
+                {
+                    ReturnErrorOnFailure(encoder.Encode(session));
+                }
             }
             return CHIP_NO_ERROR;
         });

src/app/clusters/webrtc-transport-requestor-server/webrtc-transport-requestor-cluster.cpp

@@ -67,13 +67,21 @@ DataModel::ActionReturnStatus WebRTCTransportRequestorServer::ReadAttribute(cons
     switch (request.path.mAttributeId)
     {
     case CurrentSessions::Id:
-        return encoder.EncodeList([this](const auto & listEncoder) -> CHIP_ERROR {
-            for (auto & session : mCurrentSessions)
-            {
-                ReturnErrorOnFailure(listEncoder.Encode(session));
-            }
-            return CHIP_NO_ERROR;
-        });
+        // CurrentSessions is a fabric-scoped attribute that must only return sessions belonging to the accessing fabric.
+        {
+            FabricIndex accessingFabricIndex = encoder.AccessingFabricIndex();
+            return encoder.EncodeList([this, accessingFabricIndex](const auto & listEncoder) -> CHIP_ERROR {
+                for (auto & session : mCurrentSessions)
+                {
+                    // Only encode sessions that belong to the accessing fabric
+                    if (session.GetFabricIndex() == accessingFabricIndex)
+                    {
+                        ReturnErrorOnFailure(listEncoder.Encode(session));
+                    }
+                }
+                return CHIP_NO_ERROR;
+            });
+        }
     case ClusterRevision::Id:
         return encoder.Encode(kRevision);
     case FeatureMap::Id: